Ok so the car has been running great. Just rolled 117k and decided its time to seafoam it. So I add 1pt into gas tank that is 7/8 full. Start the car up. Let it run 1 minute and begin to rev slowly and at 3krpm there's this hissing/suction sound. Please tell me its just the seafoam working and not something critical.

 

Evap air leak probably if it's high-pitched. You might start throwing a code soon. Mine was a evap purge valve.

 

So....it is ok to drive? Would I notice loss of power?

 

I waited a good six months and 25k miles. I did notice a gradual power loss, but it was corrected by resetting the ECU.